SQL & Data Extraction

📌 Planned placeholder page: this page is reserved for "SQL & data extraction: extraction questions (granularity / definition / window), high-frequency patterns (window functions, conditional aggregation), performance intuition (partition pruning, pre-aggregation), and sharing consistent definitions via views (database fundamentals link to Backend)". The content will be filled in progressively.

Planned Content

• [ ] Extraction three questions: granularity / definition / time window
• [ ] Window functions and conditional aggregation patterns with SQL examples
• [ ] Performance intuition: partition pruning, pushdown, pre-aggregation
• [ ] Reusable CTEs and shared views for consistent definitions
• [ ] Common pitfalls: join fan-out, null handling, full-table scans

Next Steps

• [ ] Complete this page item by item against the planning checklist in the Domain Overview
• [ ] Add runnable examples and pitfall records for each entry
• [ ] Change the status from "Planned" to "Collected" when done

For writing guidelines, please refer to the Writing Guide.